Radio communication system, base station apparatus, and radio communication method

Abstract

To secure a constant level or more of radio communication quality for each user equipment performing radio communication with a base station apparatus, and to increase the number of user equipment which the base station apparatus can accommodate under a condition of assuring the radio communication quality. In a radio communication system where there exist a base station apparatus having multiple antennas and user equipment for performing radio communication with a first antenna group including one or more of the antennas, the first antenna group is made configurable for each user equipment individually, and addition / deletion of the antenna to / from the first antenna group is performed based on the communication quality of each user equipment so that the number of antennas within the first antenna group may be minimized within a range satisfying a required value of the communication quality between the base station apparatus ad the user equipment.

Description

CLAIM OF PRIORITY[0001]The present application claims priority from Japanese patent application JP 2011-066063 filed on Mar. 24, 2011, the content of which is hereby incorporated by reference into this application.FIELD OF THE INVENTION[0002]The present invention relates to a radio communication system, a base station apparatus, and a radio communication method, and more specifically, to a radio communication system which assures radio communication quality, a base station apparatus, and a radio communication method.BACKGROUND OF THE INVENTION[0003]As a background art of this technology field, there is LTE (Long Term Evolution) which is a cellular system to which OFDMA (Orthogonal Frequency Division Multiple Access)-MIMO (Multiple Input Multiple Output) technology is applied. For example, 3GPP, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures,” TS36.213, v9.0.1, 2009 / 12 discloses a communication procedure in a radio physical layer between a base statio...

AI Technical Summary

Benefits of technology

[0009]In consideration the above points, the present invention has objects to assure radio communication quality equal to or more than the constant level to the each user equipment performing radio communication with the base station apparatus, and to increase the number of pieces of user equipment which the base station apparatus can accommodate under a condition of assuring the radio communication quality.

[0010]In the radio communication system in which there are a base station apparatus having multiple antennas and user equipment for performing radio communication with a first antenna group comprised of one or more of the antennas, the problem is solved by the radio communication method that is characterized in that the first antenna group is made configurable for each of the user equipment individually, and addition or deletion of the antenna to / from the first antenna group of the terminal is performed based on communication quality of the each user equipment so that the number of antennas within the first antenna group may be minimized within a range which satisfies a required value of the communication quality between the base station apparatus and the user equipment.

[0012]According to one solution of the present invention, there is provided a radio communication system that is characterized by having: user equipment; and a base station apparatus equipped with a controller which selects one or more antennas which should be within an antenna group based on the quality of communication performed between the base station apparatus and the user equipment through one or more antennas among the antennas and the number of antennas within the antenna group, and communicates with the user equipment through the first antenna group comprised of the selected antennas. Moreover, in the above-mentioned radio communication system, there is provided a radio communication system in which the first antenna group is configured for each user equipment, the antenna is added or deleted to / from the first antenna group being set up for the user equipment so that the communication quality between the base station apparatus and the user equipment may satisfy a lower limit of the required value of the communication quality and the number of antennas within the first antenna may be minimized, or the communication quality may fall within a range defined by the lower limit of the required value and an upper limit of the required value of the communication quality, and the base station apparatus communicates with the user equipment using at least the antennas of the first antenna group.

[0013]According to another solution of the present invention, there is provided a base station apparatus which has multiple antennas for performing radio communication with user equipment, and an antenna group controller which makes up a first antenna group with one or more of the antennas, and adds or deletes the antenna to / from the first antenna group being set up for the user equipment so that the communication quality between the base station apparatus and the user equipment may satisfy the lower limit of the required value of the communication quality and the number of antennas within the first antenna group may be minimized or the communication quality may fall within a range which is defined by the lower limit of the required value and the upper limit of the required value of the communication quality, in which the base station apparatus communicates with the user equipment using at least the antennas of the first antenna group.

[0014]According to further another solution of the present invention, there is provided a radio communication method using a base station apparatus which has multiple antennas and performs radio communication with the user equipment through the first antenna group comprised of one or more antennas of the antennas, having the steps of: configuring the first antenna group for each user equipment; and adding or deleting the antenna to / from the first antenna group being set up for the user equipment so that the communication quality between the base station apparatus and the user equipment may satisfy the lower limit of the required value of the communication quality and the number of antennas within the first antenna group may be minimized or the communication quality may fall within a range which is defined by the lower limit of the required value and the upper limit of the required value of the communication quality; in which the base station apparatus communicates with the user equipment using at least the antennas of the first antenna group.

[0015]According to the present invention, it is possible to assure the radio communication quality equal to or more than the constant level for each user equipment performing radio communication with the base station apparatus and to increase the number of pieces of user equipment which the base station apparatus can accommodate under a condition of assuring the radio communication quality.

Problems solved by technology

H8 (1996)-186857 adds the base station when an improvement quantity of a certain amount or more is generally expected compared to a case of communicating with a single base station, and does not assure the communication quality.

The technology of Japanese Unexamined Patent Application Publication No. 2010-010968 controls all pieces of user equipment simultaneously, and does not pay attention on the communication quality of each individual terminal.

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